379 research outputs found
Postpyloric enteral nutrition in the critically ill child with shock: a prospective observational study
<p>Abstract</p> <p>Background</p> <p>Tolerance to enteral nutrition in the critically ill child with shock has not been studied. The purpose of the study was to analyze the characteristics of enteral nutrition and its tolerance in the critically ill child with shock and to compare this with non-shocked patients.</p> <p>Methods</p> <p>A prospective, observational study was performed including critically ill children with shock who received postpyloric enteral nutrition (PEN). The type of nutrition used, its duration, tolerance, and gastrointestinal complications were assessed. The 65 children with shock who received PEN were compared with 461 non-shocked critically ill children who received PEN.</p> <p>Results</p> <p>Sixty-five critically ill children with shock, aged between 21 days and 22 years, received PEN. 75.4% of patients with shock received PEN exclusively. The mean duration of the PEN was 25.2 days and the maximum calorie intake was 79.4 kcal/kg/day. Twenty patients with shock (30.7%) presented gastrointestinal complications, 10 (15.4%) abdominal distension and/or excessive gastric residue, 13 (20%) diarrhoea, 1 necrotising enterocolitis, and 1 duodenal perforation due to the postpyloric tube. The frequency of gastrointestinal complications was significantly higher than in the other 461 critically ill children (9.1%). PEN was suspended due to gastrointestinal complications in 6 patients with shock (9.2%). There were 18 deaths among the patients with shock and PEN (27.7%). In only one patient was the death related to complications of the nutrition.</p> <p>Conclusion</p> <p>Although most critically ill children with shock can tolerate postpyloric enteral nutrition, the incidence of gastrointestinal complications is higher in this group of patients than in other critically ill children.</p
Modeling Activity and Target-Dependent Developmental Cell Death of Mouse Retinal Ganglion Cells Ex Vivo
Programmed cell death is widespread during the development of the central nervous system and serves multiple purposes including the establishment of neural connections. In the mouse retina a substantial reduction of retinal ganglion cells (RGCs) occurs during the first postnatal week, coinciding with the formation of retinotopic maps in the superior colliculus (SC). We previously established a retino-collicular culture preparation which recapitulates the progressive topographic ordering of RGC projections during early post-natal life. Here, we questioned whether this model could also be suitable to examine the mechanisms underlying developmental cell death of RGCs. Brn3a was used as a marker of the RGCs. A developmental decline in the number of Brn3a-immunolabelled neurons was found in the retinal explant with a timing that paralleled that observed in vivo. In contrast, the density of photoreceptors or of starburst amacrine cells increased, mimicking the evolution of these cell populations in vivo. Blockade of neural activity with tetrodotoxin increased the number of surviving Brn3a-labelled neurons in the retinal explant, as did the increase in target availability when one retinal explant was confronted with 2 or 4 collicular slices. Thus, this ex vivo model reproduces the developmental reduction of RGCs and recapitulates its regulation by neural activity and target availability. It therefore offers a simple way to analyze developmental cell death in this classic system. Using this model, we show that ephrin-A signaling does not participate to the regulation of the Brn3a population size in the retina, indicating that eprhin-A-mediated elimination of exuberant projections does not involve developmental cell death
Modelling and mapping regional-scale patterns of fishing impact and fish stocks to support coral-reef management in Micronesia
Aim: Use a fishery‐independent metric to model and map regional‐scale fishing impact, and demonstrate how this metric assists with modelling current and potential fish biomass to support coral‐reef management. We also examine the relative importance of anthropogenic and natural factors on fishes at biogeographical scales.
Location: Reefs of five jurisdictions in Micronesia.
Methods: A subset of 1,127 fish surveys (470 surveys) was used to calculate site‐specific mean parrotfish lengths (a proxy for cumulative fishing impact), which were modelled against 20 biophysical and anthropogenic variables. The resulting model was extrapolated to each 1 ha reef cell in the region to generate a fishing impact map. The remaining data (657 surveys) were then used to model fish biomass using 15 response variables, including fishing impact. This model was used to map estimated current regional fish standing stocks and, by setting fishing impact to 0, potential standing stocks.
Results: Human population pressure and distance to port were key anthropogenic variables predicting fishing impact. Total fish biomass was negatively correlated with fishing, but the influence of natural gradients of primary productivity, sea surface temperature, habitat quality and larval supply was regionally more important.
Main conclusions: Mean parrotfish length appears to be a useful fishery‐independent metric for modelling Pacific fishing impact, but considering environmental covariates is critical. Explicitly modelling fishing impact has multiple benefits, including generation of the first large‐scale map of tropical fishing impacts that can inform conservation planning. Using fishing impact data to map current and potential fish stocks provides further benefits, including highlighting the relative importance of fishing on fish biomass and identifying key biophysical variables that cause maximum potential biomass to vary significantly across the region. Regional‐scale maps of fishing, fish standing stocks and the potential benefits of protection are likely to lead to improved conservation outcomes during reserve network planning
Molecular pathways involved in the synergistic interaction of the PKCβ inhibitor enzastaurin with the antifolate pemetrexed in non-small cell lung cancer cells
Conventional regimens have limited impact against non-small cell lung cancer (NSCLC). Current research is focusing on multiple pathways as potential targets, and this study investigated molecular mechanisms underlying the combination of the PKCβ inhibitor enzastaurin with the multitargeted antifolate pemetrexed in the NSCLC cells SW1573 and A549. Pharmacologic interaction was studied using the combination-index method, while cell cycle, apoptosis induction, VEGF secretion and ERK1/2 and Akt phosphorylation were studied by flow cytometry and ELISAs. Reverse transcription–PCR, western blot and activity assays were performed to assess whether enzastaurin influenced thymidylate synthase (TS) and the expression of multiple targets involved in cancer signaling and cell cycle distribution. Enzastaurin-pemetrexed combination was highly synergistic and significantly increased apoptosis. Enzastaurin reduced both phosphoCdc25C, resulting in G2/M checkpoint abrogation and apoptosis induction in pemetrexed-damaged cells, and GSK3β and Akt phosphorylation, which was additionally reduced by drug combination (−58% in A549). Enzastaurin also significantly reduced pemetrexed-induced upregulation of TS expression, possibly through E2F-1 reduction, whereas the combination decreased TS in situ activity (>50% in both cell lines) and VEGF secretion. The effects of enzastaurin on signaling pathways involved in cell cycle control, apoptosis and angiogenesis, as well as on the expression of genes involved in pemetrexed activity provide a strong experimental basis to their evaluation as pharmacodynamic markers in clinical trials of enzastaurin-pemetrexed combination in NSCLC patients
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV
The production of b jets in association with a Z/gamma* boson is studied
using proton-proton collisions delivered by the LHC at a centre-of-mass energy
of 7 TeV and recorded by the CMS detector. The inclusive cross section for
Z/gamma* + b-jet production is measured in a sample corresponding to an
integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross
section with Z/gamma* to ll (where ll = ee or mu mu) for events with the
invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level
with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and
the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.)
+(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also
studied and found to be in agreement with the predictions made by the MadGraph
event generator with the parton shower and the hadronisation performed by
PYTHIA.Comment: Submitted to the Journal of High Energy Physic
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Diagnosis and treatment of musculoskeletal chest pain: design of a multi-purpose trial
<p>Abstract</p> <p>Background</p> <p>Acute chest pain is a major health problem all over the western world. Active approaches are directed towards diagnosis and treatment of potentially life threatening conditions, especially acute coronary syndrome/ischemic heart disease. However, according to the literature, chest pain may also be due to a variety of extra-cardiac disorders including dysfunction of muscles and joints of the chest wall or the cervical and thoracic part of the spine. The diagnostic approaches and treatment options for this group of patients are scarce and formal clinical studies addressing the effect of various treatments are lacking.</p> <p>Methods/Design</p> <p>We present an ongoing trial on the potential usefulness of chiropractic diagnosis and treatment in patients dismissed from an acute chest pain clinic without a diagnosis of acute coronary syndrome. The aims are to determine the proportion of patients in whom chest pain may be of musculoskeletal rather than cardiac origin and to investigate the decision process of a chiropractor in diagnosing these patients; further, to examine whether chiropractic treatment can reduce pain and improve physical function when compared to advice directed towards promoting self-management, and, finally, to estimate the cost-effectiveness of these procedures. This study will include 300 patients discharged from a university hospital acute chest pain clinic without a diagnosis of acute coronary syndrome or any other obvious cardiac or non-cardiac disease. After completion of the clinic's standard cardiovascular diagnostic procedures, trial patients will be examined according to a standardized protocol including a) a self-report questionnaire; b) a semi-structured interview; c) a general health examination; and d) a specific manual examination of the muscles and joints of the neck, thoracic spine, and thorax in order to determine whether the pain is likely to be of musculoskeletal origin. To describe the patients status with regards to ischemic heart disease, and to compare and indirectly validate the musculoskeletal diagnosis, myocardial perfusion scintigraphy is performed in all patients 2–4 weeks following discharge. Descriptive statistics including parametric and non-parametric methods will be applied in order to compare patients with and without musculoskeletal chest pain in relation to their scintigraphic findings. The decision making process of the chiropractor will be elucidated and reconstructed using the CART method. Out of the 300 patients 120 intended patients with suspected musculoskeletal chest pain will be randomized into one of two groups: a) a course of chiropractic treatment (therapy group) of up to ten treatment sessions focusing on high velocity, low amplitude manipulation of the cervical and thoracic spine, mobilisation, and soft tissue techniques. b) Advice promoting self-management and individual instructions focusing on posture and muscle stretch (advice group). Outcome measures are pain, physical function, overall health, self-perceived treatment effect, and cost-effectiveness.</p> <p>Discussion</p> <p>This study may potentially demonstrate that a chiropractor is able to identify a subset of patients suffering from chest pain predominantly of musculoskeletal origin among patients discharged from an acute chest pain clinic with no apparent cardiac condition. Furthermore knowledge about the benefits of manual treatment of patients with musculoskeletal chest pain will inform clinical decision and policy development in relation to clinical practice.</p> <p>Trial registration</p> <p>NCT00462241 and NCT00373828</p
Effects of Marine Reserves versus Nursery Habitat Availability on Structure of Reef Fish Communities
No-take marine fishery reserves sustain commercial stocks by acting as buffers against overexploitation and enhancing fishery catches in adjacent areas through spillover. Likewise, nursery habitats such as mangroves enhance populations of some species in adjacent habitats. However, there is lack of understanding of the magnitude of stock enhancement and the effects on community structure when both protection from fishing and access to nurseries concurrently act as drivers of fish population dynamics. In this study we test the separate as well as interactive effects of marine reserves and nursery habitat proximity on structure and abundance of coral reef fish communities. Reserves had no effect on fish community composition, while proximity to nursery habitat only had a significant effect on community structure of species that use mangroves or seagrass beds as nurseries. In terms of reef fish biomass, proximity to nursery habitat by far outweighed (biomass 249% higher than that in areas with no nursery access) the effects of protection from fishing in reserves (biomass 21% lower than non-reserve areas) for small nursery fish (≤25 cm total length). For large-bodied individuals of nursery species (>25 cm total length), an additive effect was present for these two factors, although fish benefited more from fishing protection (203% higher biomass) than from proximity to nurseries (139% higher). The magnitude of elevated biomass for small fish on coral reefs due to proximity to nurseries was such that nursery habitats seem able to overrule the usually positive effects on fish biomass by reef reserves. As a result, conservation of nursery habitats gains importance and more consideration should be given to the ecological processes that occur along nursery-reef boundaries that connect neighboring ecosystems
Ecoregional Analysis of Nearshore Sea-Surface Temperature in the North Pacific
The quantification and description of sea surface temperature (SST) is critically important because it can influence the distribution, migration, and invasion of marine species; furthermore, SSTs are expected to be affected by climate change. To better understand present temperature regimes, we assembled a 29-year nearshore time series of mean monthly SSTs along the North Pacific coastline using remotely-sensed satellite data collected with the Advanced Very High Resolution Radiometer (AVHRR) instrument. We then used the dataset to describe nearshore (<20 km offshore) SST patterns of 16 North Pacific ecoregions delineated by the Marine Ecoregions of the World (MEOW) hierarchical schema. Annual mean temperature varied from 3.8°C along the Kamchatka ecoregion to 24.8°C in the Cortezian ecoregion. There are smaller annual ranges and less variability in SST in the Northeast Pacific relative to the Northwest Pacific. Within the 16 ecoregions, 31–94% of the variance in SST is explained by the annual cycle, with the annual cycle explaining the least variation in the Northern California ecoregion and the most variation in the Yellow Sea ecoregion. Clustering on mean monthly SSTs of each ecoregion showed a clear break between the ecoregions within the Warm and Cold Temperate provinces of the MEOW schema, though several of the ecoregions contained within the provinces did not show a significant difference in mean seasonal temperature patterns. Comparison of these temperature patterns shared some similarities and differences with previous biogeographic classifications and the Large Marine Ecosystems (LMEs). Finally, we provide a web link to the processed data for use by other researchers
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